well.. it depends. You didn't really specify goals, which is the most important thing. In many cases you are correct. Somewhat related see Vanguard's research

well.. it depends. You didn't really specify goals, which is the most important thing. In many cases you are correct. Somewhat related see Vanguard's research "Dollar-cost averaging just means taking risk later" [1] which finds lump sum investing is better in ~2/3 of the cases they considered. They had a specific time horizon. Individual's have unique situations and goals and should consider those instead of just dumping everything into an s&p index fund asap. Maybe an individual is more sensitive to sequence risk at different points in his life? There is an entire profession (financial planners) which allows you to outsource these decisions to if you want. Same for the spending part of retirement (hint: most common advice (bond/stock mix) is exactly the opposite of what it should be e.g. "Rising Equity Glidepath" [2]) [1] https://pressroom.vanguard.com/nonindexed/7.23.2012_Dollar-cost_Averaging.pdf https://pressroom.vanguard.com/nonindexed/7.23.2012_Dollar-c... [2] https://www.kitces.com/blog/should-equity-exposure-decrease-in-retirement-or-is-a-rising-equity-glidepath-actually-better/ https://www.kitces.com/blog/should-equity-exposure-decrease-...